Strapping machine



ov. ma@ HJ. T APLIN 2,135,920

STRAPPING MACHINE Filed D80. 14, 1936 i 3 Sheets-Sheet l Nov.. 8, 1938. H. J. TAPLIN 2y35920 STRAPPING MACHINE Filed Dec. 14, 1936 5 SheetsSheet 2 Nw. s, 138. H J TAPUN 2,135,920

STRAPPING MACHINE 45 l l/ 2 21 27M ,3 8

Patented Nov. 8, 1938 UNITED STATES PATENT OFFICE STRAPPING MACHINE Harold John Taplin, London, England, assignor to Gerrard Industries Limited, London, England 6 Claims.

This invention relates to the strapping of packages and other articles.

The invention has for object to provide improved. apparatus relating to strapping with wire 5 and other materials, the ends of which material are joined by twisting or other equivalent jointforming operations, such as crushing or bending.

It is an object of the invention to provide a hand-operated strapping machine in which an oscillating member is operatively connected to carry out the twisting or other joint forming operation during both strokes of its oscillation.

It is a further object of the invention to provide a machine for making a twisted joint in which two or more twister pinions or the like are arranged for successive operation.

With these and other objects in view, the invention consists in the improved combinations and arrangements contained in the embodiments now to be described in detail, novel features of which are set out in the claims which follow.

In the drawings#- Figure 1 is a front elevation, partly in section, of one form of machine, parts being broken away, Figure 2 is a plan view of part of the same machine,

Figure 3 is a front sectional elevation of part of a modified form of machine,

Figure 4 is a plan view of the parts shown in .Figure 3,

Fig-ure 5 is a front elevation of the machine shown in Figures 3 and 4, and

Figures 6 and '7 show examples of the knots made by the machine of Figures 1 and 2 and Figures 3, 4 and 5 respectively.

The machine shown in Figures 1 and 2 is mounted on a base I and has right and left hand. twisting pinions 2 and 3 respectively arranged to be operated by a common operating lever 4 through timing gears 5 and 5 which are mounted on a shaft l. 'I'he shaft I is carriedin bearings in members B and 9 upstanding from the base I, and also has freely mounted upon it the operating lever 4. The timing gear 6 is freely "i" mounted upon the shaft 'I whilst the timing gear 5 is keyed to the shaft as at 31.

The operating lever 4 carries spring-pressed clutch dogs ID and II arranged to engage slots or recesses 4I! and 4I formed in the inner faces of the gears 5 and 6 respectively; two such slots are formed in the face of each gear at diametrically opposed positions.

The slots 4I are so shaped that the timing gear 6 is positively engaged by the dog II for driving during the forward stroke of the lever 4, but that (Cl. MII-93) the dog slips out of the slot and comes to ride on the face of the gear during the backward stroke. The slots 40 are shaped so that the gear 5, pinion 2 and the shaft 'I are driven on the backward stroke of the lever 'I but remain idle during the forward stroke.

Since there are two diametrically arranged slots in each gear, the dog which, has been riding on the face of the respective gear during any particular stroke of the handle 4 slips into a slot at the end of the stroke ready to take up the drive during the next stroke.

Spring-pressed plungers 42 and 43 carried by the members 8 and 9, are provided to engage diametrically opposed holes 44 in the faces of the gears 5 and 6 to hold them against rotation except when positively driven by the lever 4.

In addition to the parts already mentioned, the machine comprises means for locating and retaining the wire during the operation of the machine, means for tensioning the wire about the article to be strapped and means for cutting oi the end of the wire, as will appear below.

In the use of the machine, the end of a length of wire, drawn, preferably, from a coil, is passed between a pivoted spring-pressed wire-gripper I3 and the associated anvil I4, to abut against a stop-plate I5 and is gripped by the gripper I3. Its end having thus been located and'anchored the wire is inserted in the slots of the twister pinions 2 and 3 and in the holding slot I5, and is passed round the article which is to be strapped; the portion which then runs across the top of the article from left to right as seen in the drawings, and leads to the free end, or the coil as the case may be, is inserted in the slots of the twister pinions and the holding slot I6, to lie against the bight of wire already in these slots, and between the pivoted spring-pressed wire-grippers I'I and I8 and their associated anvils I9 and 20. A pivoted wire-retaining latch 2l is provided to retain the wire in position during the operation of the machine. v

It will be seen from the drawings that the distance separating the pinions 2 and 3 is twice that separating each pinion from the nearest wire holding means, that is between the pinion 3 and the holding slot I6 and between the pinion 2 and the adjacent edge of the anvil I4; moreover no provision is made for holding the wire between the two pinions.

The gripper I8 forms part of the wire-tensioning mechanism and is carried by a member 23 which is slidably mounted on a shaft 24. The member 23 isformed with a helical cam-face 25 and a similar cam-face 21 of opposite hand is formed on a xed member 28 on which the gripper I1 is pivotally mounted. A member 29, having an operating handle 30, is mounted on the shaft 24 between the cam faces 26 and 21 and itself has cam faces 3I and 32 for co-operating with these cam faces. A spring 33 mounted on the shaft 24 between the slidable member 23 and a plate 34 tends to urge the member 23 towards the left and to maintain engagement between the respective cam faces.

It will be seen from Figure 1 that the pivoted grippers I1 and I 8 are self-locking to prevent' relative movement of the wire in one direction, that is from right to left as seen in the drawings, but will automatically pivot to allow relative movement in the other direction. Thus when the tensioning handle 30 is rotated 4about the axis of the shaft 24, the cam action of the faces 26 and 3I and 21 and 32 respectively causes the gripper I8 to move to the right, drawing with it the wire which slides between the gripper I1 and anvil I9. Upon the return stroke of the handle 3D, the member 23 is returned toward the left by its spring 33, the gripper I8 sliding over the wire, which is held by the gripper I1, to grip it in a fresh place ready for the next operative stroke of the handle 30. The tensioning of the wire about the article can be continu-ed, by repeated strokes of the handle 30, until the desired tension is obtained, this being determined either by the operator or by an automatic clutch inserted between the member 23 and its operating handle 30.

When the tensioning of the wire has been completed, the operator effects the forward stroke of the lever 4, during which the pinion 3 is rotated by the timing gear 6, rotating freely on its shaft 1. This rotation of the pinion 3 results in the two bights of wire which pass through its slot being twisted about each other twice between the pinion 3 and the slot I6 and twice, in the opposite sense, between the two pinions 2 and 3, there being, as shown, a 4:1 reduction ratio between the timing gears and the pinions. Upon the completion of the forward stroke of the lever 4, the operator reverses its direction and eifects the re. turn stroke, during which the gear 5 and the shaft 1 are rotated in theY reverse direction. This rotation results in the pinion 2 being rotated in the direction opposite to that in which the pinion 3 was rotated 4and the two bights of wire are twisted about each other twice between the pinion 2 and the edge of the anvil I4, these twists being in the same sense as those previously formed between the pinion 3 and the slot I6. During this rotation of the pinion 2 two further twists are formed in the wire between the two pinions, these twists being in the same sense as those previously formed in these portions of the bights of wire. The completed knot thus has four twists in the same sense, situated between two sets of two twists each in the opposite sense, all the twists being of approximately the same pitch. i

During the rotation of the timing gear 5, the rotation of the shaft 1, which is keyed to it, causes the operation of a wire-severing. device 35 which is arranged to sever the outer bight only, that is therbight leading to the free end or to the coil. The wire severing device is operated through a cam 45 keyed to the shaft 1.

From the above description it will be seen that the end part of the knot remote from the'anchored end is flrst'completed (by rotation of the pinion 3) and the wire is severed near this com-- of the other end part of the knot. This prevents any weakness resulting from the neck of the Wire behind the cut being twisted on its own axis when the cut olf end is free.

Other advantageous features of the machine just described concern the prevention of wastage, especially when wire from a coil is used.

The use of stop-plate I5 enables the end of each length of Wire to be located and thus determines the correct length of wire for each operation.

Owing to the slope of the surface of the anvil I4, the anchored end of the wire is pushed down when tension is applied and no wire need be cut off at this end to make a neat joint.

During tensioning, wire is fed back toward the coil in a straight path and is cut off (being thereby tucked down sufficiently) close to the end of the joint. There is thus no waste of wire, whatever, since the severed end of the Wire from the coil forms the end of the next loop which is pushed against the stop-plate I5.

Figures 3, 4 and 5 illustrate a machine having but one twister pinion and designed to produce a joint comprising two sets of three twists each in opposite senses. In this machine, the devices provided for gripping, locating, retaining and stretching the wire are similar to those of the machine illustrated by Figures l and 2, and, while such parts are omitted from Figures 3 and 4, they appear in Figure 5 and in such Figure 5 are designated by the same reference numerals as similar parts in Figure 1.

The twister pinion 2 is in driving engagement with a timing gear 5I which is mounted for rotation about the axis of a shaft 1, borne in bearings in members 8 and 9 upstanding from the base I.

The timing gear 5I is mounted upon and keyed at 64 to a collar 65 Yof a bevel wheel 54 which is carries a pair of pivoted spring-pressed dogs 6U and 6I, which are arranged to engage slots or recesses in the peripheral surfaces of the bevel Wheels 54 and 55 respectively. These dogs are so formed that, during the forward stroke of the lever 4 from the position shown in plan in Figure 2, the dog 6| drives the bevel wheel 55 through positive engagement with the slot in that wheel, whilst the dog 60 slides out of the slot in the wheel 54, depressing its spring, and rides over the surface at the wheel which is driven through the train 55, 5B and transmits drive to the timing gear 5I through the key 64.

The directions of rotation of the wheels 54 and 55 are opposed, so that, at the conclusion of the forward stroke of revolution of the lever 4, the dog 60 again slips into the slot which it left at the beginning of the stroke. During the return stroke of the lever 4, owing to the shape of the dogs, the dog 50 drives the wheel 54 through positive engagement with the associated slot, whilst the dog 6I leaves the slot which it had previously engaged and slides over the peripheral surface of the wheel 55 to engage the slot again at the completion of the stroke.

Owing to the alternate driving engagement of the lever 4 with the bevel wheels and the provision of the idler wheel 56, the direction of rotation of the timing gear, and thus of the twisting pinion 2, is constant.

The shaft 1 is also driven in constant direction and operates wire-severing mechanism by means of a cam 45 keyed to the shaft.

A spring-pressed plunger 42 is provided in the member 8 to co-operate with a hole 44 in the timing gear I to locate the latter at the completion of the return stroke of the operating lever.

I claim:-

1. A hand-operated strapping machine comprising an oscillating lever or the like, a twisting pinion, unidirectional clutches for connecting said oscillating lever or the like to said twisting pinion during oscillation in either direction, and reversing gearing through which said oscillating lever or the like is connected to said twisting pinion during oscillation in one direction.

2. A hand-operated strapping machine comprising an oscillating member, a twisting pinion, reversing gearing comprising a pair of bevel wheels and a common idle bevel wheel, and unidirectional clutches whereby said oscillating member is connected to said twisting pinion during oscillation in either direction, the connection during oscillation in one direction being through said reversing gearing.

3. A hand-operated strapping machine comprising a twisting pinion, an oscillating member, and mechanism whereby said oscillating member is operatively connected to said twisting pin- A.ion to rotate it in the same direction during oscillation of said member in either direction.

4. A hand-operated strapping machine cornprising an oscillating lever, a twisting pinion, a

gear wheel meshing with said twisting pinion, a unidirectional clutch device for connecting said oscillating lever to said gear wheel to rotate it during oscillation in one direction, reversing gearing, and a second unidirectional clutch device for connecting said oscillating lever to said twisting pinion through said reversing gearing during oscillation in the other direction.

5. A hand-operated strapping machine comprising an oscillating member, a twisting pinion, reversing gearing comprising a pair of toothed wheels and a common idle wheel meshing with said pair of toothed wheels, a unidirectional clutch device for connecting said oscillating member to said twisting pinion during oscillation in one direction, and a second unidirectional clutch device for connecting said oscillating member to said twisting pinion during oscillation in the other direction, the connection of said oscillating member to said twisting pinion during oscillation in one direction being through said reversing gearing.

6. A hand-operated strapping machine comprising a twisting pinion, an oscillating member, means for connecting said oscillating member to said twisting pinion during oscillation in one direction to rotate it in a certain direction, and means for connecting said -oscillating member to said twisting pinion during oscillaton in the opposite direction to rotate it in the said certain direction.

HAROLD JOHN TAPLIN. 

